Justify that when a ball is thrown upward vertically ,the initial velocity is equal to the final velocity when the ball lands on the ground provided there is no interruption in the air and time up is equal to time down can anyone please help me with this.

When a ball is thrown up in the air, the ball's velocity is initially upward. Since gravity pulls the object toward the earth with a constant acceleration g, the magnitude of velocity decreases as the ball approaches maximum height.

At the highest point in its trajectory, the ball has zero velocity, and the magnitude of velocity increases again as the ball falls back toward the earth.

Hope it helps!  :>

i think the answer would be b

a.   mass number from atomic number